Storefront and curtainwall framing systems are well known in which frame members are erected in a grid-like arrangement for glazing infill panels. Such storefront and curtainwall framing systems typically employ a plurality of tubular frame members, each of which defines opposing glazing pockets in its lateral walls. Lateral edges of adjacent glazing panels are received within these glazing pockets. Most often, these glazing pockets are of unequal depth and are referred to as "deep" and "shallow" glazing pockets.
When it becomes necessary to locate a doorway in a storefront or curtainwall framing system, the doorway is typically framed out using the same frame members employed for glazing infill panels. Consequently, the frame members framing the doorway have glazing pockets formed in their lateral faces which must be trimmed to provide a suitable doorway. Depending upon whether a door is to be mounted within the doorway, the filler may comprise either a door stop or a flat filler.
The fillers originally used to trim doorways framed in curtainwall and storefront framing systems include a filler panel having forward and rearward extending flanges which are captured behind U-shaped walls defining gasket grooves formed at the exterior and the interior corners of the glazing pocket. To enable these flanges to be captured behind the walls of the gasket grooves, this type of filler had to be installed by sliding the filler longitudinally onto the frame member. Consequently, the fillers had to be installed either prior to or during the erection of the frame members and could not be installed once the framing system had been erected. Further, because it was not possible to slide such fillers longitudinally onto or off of the frame members once the curtainwall or storefront framing system had been erected, removing and replacing a damaged filler was problematic.
To address these problems, a new type of filler was designed which would permit the filler to be snapped into the frame member. This type of filler overcame the problems associated with longitudinally sliding the filler onto its corresponding frame member, permitting the filler to be installed onto the frame member after the framing system had been erected and further facilitating removal and replacement of damaged fillers subsequent to installation. Examples of this type of filler include the flush filler/center pivot door adapter, part no. 40565, and the offset pivot door adapter, part no. 40566, both manufactured by Amarlite Architectural Products; the flush filler, part no. E9-1010, manufactured by YKK; the snap-in door stop, part nos. 9257S and 9257T, manufactured by EPCO; the snap-in filler, part nos. 50-710-4224 and 50-710-6224, and the door stop snap-in, part no. 17-109-4224 and 17-109-6224, both manufactured by PPG; and the snap-in door stop with gasket, part no. FG-2145, manufactured by Vistawall.
However, this general design of snap-in filler suffers its own problems. First, the filler is dependent for mounting upon a pair of inwardly extending legs which deflect inwardly as the filler is installed to clear the U-shaped walls defining the gasket channels. Upon clearing the gasket channels, the legs then snap outwardly to engage the opposed interior and exterior walls of the glazing pocket. However, to ensure that these legs are able to deflect inwardly by an amount sufficient to clear the gasket channels and still snap outwardly into engagement with the walls of the glazing pocket without exceeding their elastic limits, the legs of the filler necessarily have to be rather long. Consequently, this design of filler is usually suitable only for use in the deep glazing pocket. Thus, if the doorway were accidentally framed with one or more shallow glazing pockets directed inwardly, this type of filler could not be used. At the very least, this design of filler requires additional care during erection of the storefront or curtainwall framing system to ensure that the deep glazing pockets are properly oriented with respect to the framed-in doorway.
Another problem associated with this design of filler is that the action of the opposed spring legs bearing against opposing walls of the glazing pocket causes a "centering" action which tends to center the filler with respect to the underlying glazing pocket. Consequently, if due to design tolerances the filler is slightly narrower than the underlying glazing pocket, a gap is formed between the edges of the filler and the adjacent edges of the glazing pocket. Even in those installations in which a door is mounted within the doorway, the gap between the interior edge of the filler and the adjacent edge of the glazing pocket is still exposed. Further, the mounting arrangement provided by the spring legs render this type of filler susceptible to "rattling" within the glazing pocket.
Efforts have been made to overcome the problems associated with this type of snap-in filler. U.S. Pat. No. 5,007,221 discloses a snap-in glazing pocket filler comprising a filler plate having flanges formed on its inner face. A pair of plastic retaining legs have sockets which engage the flanges such that the legs extend rearwardly and outwardly to engage the walls of the glazing pocket. The sockets are configured such that the legs are capable of a limited degree of rotational movement. The snap-in glazing pocket filler disclosed in the aforesaid U.S. Pat. No. 5,007,221 provides certain advantages over earlier snap-in filler designs, in that the plastic legs and the pivotable mounting arrangement permit the legs to deflect further as the glazing pocket filler is installed without reaching their elastic limit. Consequently, a shorter leg can be used, thereby making this design suitable for use in a shallow glazing pocket as well as a deep glazing pocket. However, this design still does not address other problems associated with snap-in glazing pocket fillers.